The present invention relates to a fuel pump for internal combustion engines and, more particularly, to a fuel pump suitable for use in diesel engines.
A fuel pump of the aforementioned type includes a working chamber divided by a shuttle member into two working chamber sections. A fuel to be injected is delivered to one of the working chamber sections, while the other working chamber section receives therein a fuel which pushes the shuttle member to pump the fuel in the first-mentioned working chamber section to an injection nozzle. In such a fuel pump, the supply of the fuel to one working chamber section has to overcome the force produced by the fuel residing in the other working chamber section. Thus, the fuel pressures in both working chamber sections interfere with each other through the shuttle member, so that fuel is not introduced into the working chamber section at the predetermined rate and/or a fuel is not pumped out at the predetermined rate.
Accordingly, an object of the present invention is to provide a fuel pump capable of timely pumping a fuel at a predetermined rate to each injection nozzle of an internal combustion engine to overcome the problems encountered in the prior art.